Spinal tension and pressure relieving body support apparatus

ABSTRACT

A therapeutic support apparatus comprises multiple layers of foam having different densities and memories. The support apparatus comfortably supports the weight of a user while minimizing pressure points between the user and the support apparatus. Each foam layer has a unique density and memory based upon the type of tissue the layer is intended to support. A relatively low-memory outer foam layer made from latex non-viscoelastic foam substantially supports skin and subcutaneous tissue. A relatively high-density and medium-memory intermediate layer made from polyurethane foam supports muscle tissue. A relatively high-density and high-high memory core layer made from polyurethane foam supports the spine. In combination, these layers minimize hyperextension and promote blood circulation and comfort while the support apparatus is used by a user positioned in a supine, recumbent, or sideways-lying position.

CLAIM TO PRIORITY

This application claims the benefit of U.S. Provisional Application No.60/830,363 entitled SPINAL TENSION AND PRESSURE RELIEVING BODY SUPPORTAPPARATUS and filed Jul. 12, 2006, and U.S. Provisional Application No.60/899,496, entitled PRESSURE RELIEVING BODY SUPPORT APPARATUS and filedFeb. 5, 2007, which are hereby incorporated by reference in theirentirety.

FIELD OF THE INVENTION

The present invention relates generally to mattresses and cushions. Morespecifically, the present invention relates to an apparatus forsupporting a human body in a supine, recumbent, seated or sideways-lyingposition in a manner that relieves tension and pressure on the spine andpromotes blood circulation.

BACKGROUND OF THE INVENTION

Nearly 80 million or fifty percent of working Americans are disabled byback pain at some time in their lives. It is estimated that one-third ofmen and one-half of women will prematurely retire from their careersbecause of back pain. Approximately 400 billion dollars are spent oncare of the spine within the health care system annually. It isestimated that by 2015 Medicare and Medicaid will spend nearly onetrillion dollars on medically compromised individuals needing long-termcare and who are susceptible to developing nosocomial pressure ulcerswhile in health care facilities.

Many types of mattresses, cushions, and other therapeutic pads have beendeveloped to treat back pain, spinal disorders, and/or pressure ulcersby attempting to support and relieve pressure from the spine.Conventional mattress and box springs systems, however, often fail toprovide the relief of pressure and tension necessary for a healthy spineor optimal circulation. Conventional mattress designs, such as, forexample, mattresses that are constructed from hard plastic covers, thickhigh-density filler material, or springs, such as, for example, steelsprings, can create pressure points on the shoulders, hips and thighs ofa user. Specifically, the weight of the user compresses such aconventional mattress such that the mattress develops pressure points onthe skin and at prominent bony sites of the user. The resulting pressurepoints can impede circulation and, in turn, exacerbate compromisedcirculation in a user already suffering from a circulatory disorder suchas, for example, diabetes and congestive heart failure. This, in turn,increases the likelihood that the user will develop a dermatologicdisorder such as pressure ulcers or tissue necrosis. Similar problemsare also often associated with the cushions used to provide a paddedseat in a wheelchair.

Many conventional mattresses can also distort the spine into eithersacral hyperextension while a user is laying on his or her back orlateral distortion while a user is lying on his or her side. Sacralhyperextension can cause facet imbrications and associated foraminalnarrowing—the leading cause of resting-induced chronic back pain andoften associated with most spinal pain syndromes in the working classand the elderly—which can disrupt nerve communication and impair venousdrainage and arterial flow. Poor spinal support while lying on the sidecan result in lateral distortion and tension in spinal joints and spinalmuscles. This is often responsible for facet syndrome, a classicdiagnosis familiar to all pain management physicians who, whileattempting to treat the mechanical cause of poor posture-induced sleepdisorders, must resort to sedatives, anti-spasmotics, antidepressants,and anti-anxiety agents.

Yet another drawback of coil, flex steel, and foam, such as low-memoryviscoelastic “space age” foam, mattresses is their general lack of anability to relieve both pressure and tension. In the case of coil andflex steel mattresses, the pressure-relieving characteristics of themattresses are non-uniform and may even diminish in the areas betweenthe zones where the coils and flex steel provide pressure relief.

Foams can be characterized by their corresponding Indention ForceDeflection (IFD) rating, otherwise known as the Indention LoadDeflection (ILD), which is the international scale for memory and isbased on a scale ranging from 0-100. Indentation force deflection isdefined as the measure of the load-bearing capacity of flexible foam. Itis generally measured as the force in pounds required to compress afifty square inch circular indenter foot into a 4 inch thick sample nosmaller than 24 inches square to a stated percentage of the sampledinitial height. Common IFD values are generated at 25 and 65 percent ofinitial height. See http://www.pfa.org/jifsg/jifsgs15.html, incorporatedherein by reference in its entirety. The details of this measurement aredefined in reference test method ASTM D3574 which is also incorporatedherein by reference in its entirety. The IFD values identified in thepresent application are based on a twenty five percent deflection. Foamsalso have a rate of recovery. Recovery is defined as the return tooriginal dimension and properties of a foam sample after a deformingforce is removed.

In the case of foam mattresses and seat cushions, two major problemsexist, particularly with respect to low “memory” or conforming foamapplications: loss of support due to 1) body heat and 2) body weight.

Loss of support characteristic of low memory or conforming foams occursas the spine, which is the body's core and warm point(s), comes incontact with the low “memory” or viscoelastic foam. Low memory,conforming, or viscoelastic foams are designed to soften or lose I.F.D.rating and subsequent support as normal body heat is absorbed by thefoam. This low memory, conforming, or viscoelastic foam, by design,becomes more viscous or liquid-like, as it absorbs and retains heat,effectively losing its memory or ability to rebound and offer support.This loss of support occurs at precisely the spinal levels that need themost support: the thoracic curve and the sacrum.

A variety of techniques and devices have been used to reduce incidenceof pressure ulcers in medically compromised individuals and providegreater comfort to individuals confined to or spending substantialamounts of time in a bed or a wheelchair. For instance, air mattressoverlays, static and dynamic air mattresses, water mattress overlays,gel-like overlays, specialty beds, foam overlays, and various othertypes of materials and combinations of materials have been used tocreate new types of mattresses or to modify existing mattresses. Inaddition, costly motorized or dynamic devices in mattresses have alsobeen used for similar purposes. The cost, complexity, size, and/orweight of many of these products narrows the market for which suchdevices can be effectively or successfully offered.

Therefore, there is a need for an apparatus that provides comfortablesupport, promotes circulation of the blood, and relieves back pain andspinal tension without the drawbacks discussed above.

SUMMARY OF THE INVENTION

The present invention addresses the aforementioned needs of patients andother individuals for a low-cost pressure relieving, high quality bodysupport apparatus, such as, for example, a mattress, cushion, pad, andthe like, that relieves back pain and spinal tension, promotescirculation of blood, and provides comfortable support by providing amulti-density, tissue density specific, therapeutic body supportapparatus made from multiple layers of high-memory, non-conforming, ornon-viscoelastic type foam that have a high rate of recovery. Thepresent invention is an efficient and cost effective non-mechanizeddevice that meets the aforementioned needs by providing a low-cost,light-weight, durable, and easy-to-use body support apparatus.

In addition to reducing pressure points, the body support apparatus ofthe present invention provides superior tension and pressure relief tothe spine and other regions of the back. Specifically, the body supportapparatus provides the spinal support that is necessary for spinaldecompression and optimal circulation, deeper levels of sleep, andspinal rest. Pressure and tension relief is substantially uniform alongthe surface of the body support apparatus.

The body support apparatus has a contiguous design that minimizes theexistence of zones of diminished pressure or tension relief to providesubstantially uniform support to the spine. The body support apparatusgenerally comprises a core layer of relatively high-density, high-memorypolyurethane foam, an intermediate layer of relatively high-densitymedium-memory polyurethane foam, and an outer layer of relativelyhigh-density latex foam with a higher rate of recovery and memory thanlow-memory, conforming foams. In different embodiments, the presentinvention can have three or more layers of the high-density, high-memoryfoam, the medium-memory foam, and/or the high-density latex foam.

Foams with low I.F.D. ratings, popularly known as low “memory” foams,not to be confused with latex foam or higher I.F.D. rated non-conformingpolyurethane foams, have low rebound and/or memory characteristics aswell as a low rate of recovery. The inability of low memory, conforming,or viscoelastic foams to support body weight is defined by and theresult of their very low I.F.D. rating. Memory or conforming foams have,at best, a very low memory averaging between 5 and 20 on the scale, anda low rate of recovery. This low memory rating means that all mattressor seat cushion applications bearing the low memory or conformingrating, by design, degrade in their body support characteristics withthe application of sustained pressure or body heat. As a result of thepoor support offer by foams of the low memory, conforming, orviscoelastic type, pressure and heat points are created leaving patientswho are at risk of pressure ulcers more prone to necrotic skindisorders.

By having multiple layers of foam having different thickness, memories,and/or densities, the support layers of the present invention combinedcan facilitate the ability of the nervous system to become better ableto enter a rest phase during sleep, and promote improved circulation ofblood into the skin, muscles, and spinal column to more effectivelyreduce both spinal tension and pressure in the aforementioned tissues.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a body support apparatus according to anembodiment of the present invention.

FIG. 2 is a side view of a body support apparatus according to anembodiment of the present invention supporting a human body.

FIG. 3 is a side view of a body support apparatus according to anembodiment of the present invention supporting a human body.

FIG. 4 is side view of a mattress according to the prior art supportinga human body.

FIG. 5 is a partial cross-sectional view of human spine depicting normaldisc spacing and joint proximity alignment.

FIG. 6 is a partial cross-sectional view of a human spine depicting disccompression, foramen narrowing, and facet joint overlap imbrications.

FIG. 7 is a cross-sectional view of a lumbar disc, sacrum, and vertebrain a state of normal tension and pressure.

FIG. 8 is a cross-sectional view of a lumbar disc, sacrum, and vertebrain a state of abnormal tension and pressure.

FIG. 9 is a perspective view of a body support apparatus according to anembodiment of the present invention.

FIG. 10 is a perspective view of a body support apparatus according toan embodiment of the present invention.

FIG. 11 is a perspective view of a body support apparatus according toan embodiment of the present invention.

FIG. 12 is a perspective view of a body support apparatus in a hospitalenvironment according to an embodiment of the present invention.

FIG. 13 is a perspective view of a body support apparatus used with awheelchair seat according to an embodiment of the present invention.

FIG. 14 is a perspective view of a body support apparatus used with awheelchair seat according to another embodiment of the presentinvention.

FIG. 15 is a sectional view of a body support apparatus according to anembodiment of the present invention.

FIG. 16 is a cross-sectional view of a body support apparatus accordingto an embodiment of the present invention.

FIG. 17 is perspective view of an insert of a body support apparatusaccording to an embodiment of the present invention.

FIG. 18 is a side view of a body support apparatus according to anembodiment of the present invention.

FIG. 19 is an exploded view of a body support apparatus according to anembodiment of the present invention.

FIG. 20 is a cross-sectional view of a body support apparatus accordingto an embodiment of the present invention.

FIG. 21 is a perspective view of a body support apparatus according toan embodiment of the present invention.

DETAILED DESCRIPTION

A body support apparatus 100 according to an embodiment of the presentinvention is illustrated at FIG. 1. Body support apparatus 100 generallyhas multiple foam layers 120. Foam layers 120 may include core layer122, intermediate layers 124, and outer layers 126. Body supportapparatus 100 presents top surface 128. Top surface 128 of body supportapparatus 100 generally evenly redistributes the weight of a userthrough foam layers 120 to minimize pressure points between the user andbody support apparatus 100.

In direct contrast to the low-memory, conforming, or viscoelastic foamspreviously described, suitable foams according to the present disclosureexhibit generally higher memory, higher rate of recovery, and higherresistance to compression than the low-memory, conforming foams.Suitable foams according to the present disclosure can include: (1) ahigh-density latex, such as a natural latex, that is non-conforming,non-heat sensitive, and non-viscoelastic and has a higher rate ofrecovery and memory than the low-memory, non-conforming foams; (2) highdensity, high-memory polyurethane foam which is non-conforming, non-heatsensitive, and non-viscoelastic; and (3) high-density, medium-memorypolyurethane foam which is non-conforming, non-heat sensitive, andnon-viscoelastic.

Although body support apparatus 100 illustrated in FIG. I has five foamlayers 120, body support apparatus 100 can have three or more foamlayers 120 without departing from the spirit of scope of the presentinvention. Referring to foam layers 120 making up body support apparatus100, core layer 122 generally has a relatively high density,high-memory, intermediate layers 124 generally have a relatively highdensity, medium-memory, and outer layers 126 generally have a relativelyhigh density, and a higher memory and rate of recovery than low-memory,non-conforming foams described above.

Each intermediate layer 124 is generally coextensively positionedbetween core layer 122 and outer layer 126. In an example embodiment,the density of each foam layer 120 approximates the density of acorresponding body tissue such that layer 126 approximates very nearlythe density of skin and fat, layer 124 approximates the density ofmuscle, and layer 122 approximates the density of spinal ligaments anddiscs.

Foam layers 120 of body support apparatus 100 generally have differentindentation force deflections (IFDs), discussed above. The IFD valuestated within this application are examples and a range of IFD values oneither side of these stated values may be utilized in the presentinvention.

In an example embodiment of the present invention, core layer 122generally has an IFD in a range between about 75 and about 90. The IFDsof intermediate layers 124 generally can be in a range between about 29and about 39. In an example embodiment, top intermediate layer 124A hasan IFD of about 19 and bottom intermediate layer 124B has an IFD ofabout 24. By constructing body support apparatus 100 to haveintermediate layers 124 with different IFDs, body support apparatus 100can be turned over to selectively provide more or less muscle support.In an example embodiment, outer layers 126 have an IFD in a rangebetween about 19 and about 24. The upper and lower superficial layerscan be formed of a latex foam material with a significantly higher rateof recovery than low-memory conforming foams. One suitable latex foam isa breathable, natural latex foam material.

In different applications, body support apparatus 100 can simultaneouslyprovide relief and support to a user assuming a supine position, arecumbent position, or a sideways-lying position. Body support apparatus100 can also promote circulation of the blood and prevent and treatpressure ulcers. Specifically, body support apparatus 100 is made fromhigh-memory foam such that outer layer 126 is soft, yet non-collapsible,intermediate layer 124 can provide support to the musculature, and corelayer 126 is resiliently hard. Foam layers 120 can have the samethickness or different thicknesses. Referring to foam layers 120 makingup body support apparatus 100, core layer 122 is generally the thickestfoam layer 120, while outer layers 126 are generally the thinnest foamlayers 120.

Body support apparatus 100 distributes the weight of a user over topsurface 128 while still providing support to spinal region 130 of theuser. Specifically, body support apparatus 100 maintains propercurvature of spine 132 and orientation of sacrum 134 of a user, such as,for example, a user in the supine position, as depicted in FIGS. 2-3.Body support apparatus 100 contiguously and uniformly supports spinalregion 130 of a user with multiple cushioning components, or foam layers120. By distributing the weight of the user, body support apparatus 100minimizes the existence of pressure points that can lead to compromisedcirculation, sacral hyperextension, and general discomfort. In contrast,conventional mattresses 200 can promote exaggerated curving of spine 132of a user in the supine position, as depicted in FIG. 4.

Referring to FIGS. 2-3, the spinal region of a user positioned on bodysupport apparatus 100 in a supine position is shown. In an exampleembodiment, body support apparatus 100 has five foam layers 120,including single core layer 122, two intermediate layers 124, and twoouter layers 126, as depicted in FIG. 2. By having multiple intermediateand outer layers 124, 126, body support apparatus 100 can be reversible.In another embodiment, support pad has three foam layers, includingsingle core layer 122, single intermediate layer 124, and single outerlayer 126, as depicted in FIG. 3. Other embodiments of the presentinvention can have more or fewer foam layers 120 without departing fromthe spirit of scope of the present invention. In general, the existenceof multiple foam layers 120 in body support apparatus 100 reduce theincidence of pressure points between top surface 128 of body supportapparatus 100 and a user.

Foam layers 120 may be attached to each other in any number of ways.Generally, foam layers 120 are joined to one another by a continuousadhesive bonding between layers 120. In an example embodiment, foamlayers 120 are attached to other foam layers 120 with a chemicaladhesive. In one embodiment, foam layers 120 are attached using awater-based, permanent flexible, non-toxic adhesive covering at least aportion of the interface of each foam layer 120. In another embodiment,foam layers 120 are frictionally held together by the surfaces of eachfoam layer 120.

Referring to FIG. 2, outer layer 126 presents top surface 128 of bodysupport apparatus 100 on which a user can position him or herself in asupine, recumbent, or sideways-lying position. Outer layers 126 presenta tactile-comfort layer to the user and are generally self-ventilating,soft, non-collapsible, insensitive to heat, and able to providecontinuous support. Specifically, outer layers 126 of body supportapparatus 100 provide tactile comfort and dermal support to a user byhaving a density that is substantially similar to the density of humanskin and subcutaneous tissue. In an example embodiment, outer layers 126are made from latex foam. Outer layers 126 can have a thickness in arange of about one inch to about two inches. In an example embodiment,outer layers 126 have a thickness of approximately one inch. The densityof outer layers 126 can be varied so as to provide more or less supportto the skin and subcutaneous tissue.

Referring to FIG. 2, intermediate layers 124 are situated between corelayer 122 and outer layers 126. Generally, intermediate layers 124provide a muscle-support and muscle-comfort layer to a user by having amedium-memory rebound while maintaining continuous firmer high-densitysupport. Specifically, intermediate layers 124 can provide suchmusculature comfort and support by having a medium-memory rebound whilemaintaining continuous firmer medium-memory support. In an exampleembodiment, intermediate layers 124 are made of polyurethane.Intermediate layers 124 can have a thickness of between about two inchesand about four inches. In an example embodiment, intermediate layers 124have a thickness of approximately 2.5 inches and have a density ofapproximately 2.5-3.0 pounds per cubic foot. Intermediate layers 124 canthereby support the denser and heavier muscle tissue located below theskin.

Referring to FIGS. 2-3, core layer 122 is situated between intermediatelayers 124 or beneath one intermediate layer 124. Core layer 122 enablessupport pad 110 to properly support spine 132 of a user, as depicted inFIGS. 2-3. To support the spine 132, core layer 122 impedes the pelvis(not shown) and sacrum 134 from sagging into hyperextension, as depictedin FIG. 5. In contrast, as depicted in FIG. 6, conventional mattress 200tends to facilitate sagging of the pelvis (not shown) and sacrum 164into hyperextension.

Referring to FIG. 7, sacrum 134 and vertebra 136 form overlap region 138and gap 139. Similar overlap regions 138 and gaps 139 are formed betweenvertebrae 136. Within overlap regions 138 are nerve foramina. As thecurvature of spine 132 becomes more pronounced, overlap regions 138become more pronounced and clearance for nerve and blood supply isreduced by the increase in overlap and decrease in gap desired forcirculation, as depicted in FIG. 8. By impeding hyperextension, corelayer 122 thereby minimizes narrowing of nerve foramina due to excessivespinal joint overlap, such as can occur when a user positions him orherself in a supine position. When the user positions himself or herselfin a sideways position, core layer 122 similarly reduces tension andpressure on the spinal nerves by minimizing spinal sag that can causethe nerve foramina in overlap regions 138 to become offset.

Core layer 122 generally impedes hyperextension and reduces tension andpressure on the spinal nerves by having a density that can support thespine of a user weighing up to approximately four-hundred pounds. In anexample embodiment, core layer 122 is made from high-densitypolyurethane. Core layer 122 may have a thickness in the range of abouttwo inches to about five inches and has a density of approximately2.5-3.0 pounds per cubic foot. In an example embodiment, core layer 122has a thickness of approximately two inches and has a density ofapproximately 2.5-3.0 pounds per cubic foot. Core layer 122 therebysupports the denser and heavier spinal joint tissues where the nervesexit the spine by maintaining continuous support necessary for spinalrelaxation and decompression.

Referring to FIG. 9, body support apparatus 100 can include removablecover 140. Removable cover 140 can be made from any number of materialsthat do not materially affect the IFD of foam layers 120 or the overallcompressive and supportive characteristics of body support apparatus100, such as, for example, velour, natural wool blends, and othersuitable materials. In an example embodiment, removable cover 140 iswashable and substantially encloses foam layers 120. Specifically,removable cover 140 can be made from a material or contain an additiveor treatment, or both, having anti-microbial characteristics orproviding a self-ventilating liquid-barrier inner lining. In one exampleembodiment, removable cover 140 comprises a fire-retardant natural woolblend.

Referring to FIG. 10, body support apparatus 100 can include a safetycover 150 in another embodiment. Specifically, safety cover 150 can bemade from a material or contain an additive or treatment, or both,having fire-retardant or fire-resistant qualities. In an exampleembodiment, safety cover 150 meets or exceeds relevant life safety coderequirements for health care institutions, such as, for example,applicable state and federal governmental laws, rules, andadministrative regulations.

Removable cover 140 and safety cover 150 can be secured around foamlayers 120 in any number of ways. In an example embodiment, removablecover 140 or safety cover 150 is secured around foam layers 120 by azipper mechanism. In other embodiments, removable cover 140 or safetycover 150 is secured around foam layers by buttons, snaps, hook-and-loopfasteners, or other suitable fastening members.

In another embodiment of the present invention, body support apparatus100 rests upon foundation 160, as depicted in FIG. 11. Foundation 160generally includes top surface 162 and bottom surface (not shown).Foundation 160 may be made from any substantially rigid structure. Whenbody support apparatus 100 is rested upon foundation 160, bottom surface(not shown) of body support apparatus 100 is substantially coextensivewith top surface 162 of foundation 160. In an example embodiment,foundation 160 is formed from box spring 164 and foundation cover 166,as depicted in FIG. 11. In another embodiment, foundation 160 is formedfrom box spring 164 or foundation cover 166. Body support apparatus 100and foundation 160 may conformingly fit on frame 169, as depicted inFIG. 11.

Referring to FIG. 11, foundation cover 166 can be placed on top of boxspring 164, while body support apparatus 100 can be placed on top offoundation cover 166. Foundation cover 166 may be made of anysubstantially rigid material that conforms to the bottom surface of bodysupport apparatus 100 and may be selected to have any number ofthicknesses. In an example embodiment, foundation cover 166 is made fromplywood having a thickness of approximately five-eighths of one inch.Although box spring 164 and foundation cover 166 may have any number ofsizes and shapes, box spring 164 and foundation cover 166 generally havethe same size and shape as body support apparatus 100.

In another embodiment, body support apparatus 100 may be constructed soas to fit onto gurney 170 or other apparatus design to accommodate anindividual in a supine position, as depicted in FIG. 12. In anotherembodiment, body support apparatus 100 may be constructed so as to fitthe seat of wheelchair 180, as depicted in FIG. 13-14. In anotherembodiment, body support apparatus 100 can be constructed to fitspecialty institutional chairs for medically compromised individuals.

Referring to FIG. 15, in another embodiment, foam layers 120 may becontoured so as to integrate head-support region 182 and neck-supportregion 184 into body support apparatus 100. Head-support region 182 andneck-support region 184 may be integrated into a mattress.Alternatively, head-support region 182 region 182 and neck-supportregion 184 may be integrated into pillow 190, as depicted in FIG. 15.

Referring to FIGS. 16-19, in another embodiment of the presentinvention, body support apparatus 100 includes pressure-relief mattress200. In an embodiment of the present invention, pressure-relief mattress200 has a similar gradient created by tiered layers of tissuedensity-specific pressure relieving layers of foam and a relief zonewith the tiered layers. Referring to FIG. 16, pressure-relief mattress200 has bottom layer 202, top layer 204, at least two intermediateinserts 206, and relief zone 208. Bottom layer 202 is substantiallyplanar to accommodate a box spring, platform, or other support of a bed.Intermediate inserts 206 are substantially wedge-shaped, as depicted inFIG. 17, to facilitate a bumper-like edge or ridge 210. Top layer 204 issubstantially non-planar to accommodate for intermediate inserts 206.Relief zone 208 is coplanar with the at least two intermediate inserts206 and situated between top layer 204 and bottom layer 202.

Referring to FIGS. 18-19, pressure-relief mattress 200 can furtherinclude cut-away section 212 in ridge 210 to accommodate a user's limbs,such as, for example, an arm. Cut-away section 212 provides an area forresting an arm and/or extending the arm beyond the edge ofpressure-relief mattress 200. The structure of the embodiment depictedin FIGS. 16-19 may reduce the risk that a patient will roll out of bedand suffer an injurious fall.

Further example embodiments of pressure-relief mattress 200 are shown inFIGS. 20-21. Referring to FIG. 20, pressure-relief mattress 200 includesbottom layer 222, intermediate layer 224, and top layer 226. Bottomlayer 222 has first major surface 228 and second major surface 230.Bottom layer 222 comprises notch 232 at any point along the longitudinalaxis of second major surface 230. Notch 232 extends substantiallythrough bottom layer 222 to act as a hinge for bed inclinationadjustment. The annotated dimensions in FIG. 20 are examples and are notto be considered limiting in any manner.

Pressure-relief mattress 200 is depicted in FIG. 21, as set forth inU.S. Provisional Application 60/830,363. The dimensions in FIG. 21 areexamples and are not to be considered to be limiting in any manner.Pressure-relief mattress 200 provides continuous pressure relief at allpoints since the support is an integral part of the unique body supportsystem. Each point of support is created by multiple cushioningcomponents. Each foam layer 120 approximates the density of the tissueit supports.

It is to be understood that the above-described arrangements are onlyillustrative of the application for the principles of the presentinvention. Numerous modifications and alternative arrangements can bedevised without departing from the spirit and scope of the presentinvention. Thus, while the present invention has been shown in thedrawings and fully described above with particularity and detail inconnection with what is presently deemed to be the most practical andpreferred embodiments of the invention, it will be apparent to those ofordinary skill in the art that numerous modifications, including, butnot limited, to variation in size, shape, form, function, and manner ofoperation, assembly, or use may be made without departing from theprinciples and concepts set forth herein.

1. A multi-layer therapeutic body support apparatus, the apparatuscomprising: a core foam layer having a core density and a coreindentation force deflection; a top outer foam layer having a firstouter density and a first outer indentation force deflection; a firstintermediate foam layer intermediate and coextensive with the core layerand the top outer layer and having a first intermediate density and afirst intermediate indentation force deflection; and wherein the coreindentation force deflection is greater than the first intermediateindentation force deflection, and the first intermediate indentationforce deflection is greater than the first outer indentation forcedeflection.
 2. The multi-layer therapeutic body support apparatus ofclaim 1, wherein the core foam layer comprises polyurethane foam.
 3. Themulti-layer therapeutic body support apparatus of claim 2, wherein thecore density is between about 2.5 pounds per cubic foot and about 3.0pounds per cubic foot.
 4. The multi-layer therapeutic body supportapparatus of claim 1, wherein the core indentation force deflection isin the range from about 75 pounds/fifty square inches to about 90pounds/fifty square inches at twenty five percent deflection.
 5. Themulti-layer therapeutic body support apparatus of claim 1, wherein thefirst intermediate foam layer comprises polyurethane foam.
 6. Themulti-layer therapeutic body support apparatus of claim 5, wherein theintermediate density is between about 2.5 pounds per cubic foot andabout 3.0 pounds per cubic foot.
 7. The multi-layer therapeutic bodysupport apparatus of claim 1, wherein the intermediate foam indentationforce deflection is between about 29 pounds/fifty square inches attwenty five percent deflection and about 39 pounds/fifty square inchesat twenty five percent deflection.
 8. The multi-layer therapeutic bodysupport apparatus of claim 1, wherein the outer foam layer has anindentation force deflection in the range from about 19 pounds/fiftysquare inches and about 25 pounds/fifty square inches at twenty fivepercent deflection.
 9. The multi-layer therapeutic body supportapparatus of claim 1, wherein the first outer foam layer comprises latexfoam.
 10. The multi-layer therapeutic body support apparatus of claim 1,further comprising: a bottom outer foam layer having a second outerdensity and second outer indentation force deflection; a bottomintermediate layer intermediate and coextensive with the core layer andthe bottom outer layer and having a second intermediate density andsecond intermediate indentation force deflection; and wherein the coresecond indentation force deflection is greater than the secondintermediate second indentation force deflection and the secondintermediate second indentation force deflection is greater than thesecond outer second indentation force deflection.
 11. The multi-layertherapeutic body support apparatus of claim 1, further comprising araised ridge proximate at least a portion of a perimeter of theapparatus.
 12. The multi-layer therapeutic body support apparatus ofclaim 11, wherein the raised ridge is interrupted by a cut away sized toreceive an appendage of a body of a person lying on the apparatus. 13.The multi-layer layer therapeutic body support apparatus of claim 1,wherein the apparatus is a mattress.
 14. A therapeutic body supportapparatus, comprising: a core portion having a core density and a coresecond indentation force deflection; a top outer portion having a firstouter density and a first outer second indentation force deflection; afirst intermediate portion intermediate and coextensive with the coreportion and the top outer layer and having a first intermediate densityand a first intermediate second indentation force deflection; whereinthe core second indentation force deflection is greater than the firstintermediate second indentation force deflection, and the firstintermediate second indentation force deflection is greater than thefirst outer second indentation force deflection; a bottom outer portionhaving a second outer density and second outer second indentation forcedeflection; a second intermediate portion intermediate and coextensivewith the core portion and the bottom outer portion and having a secondintermediate density and a second intermediate second indentation forcedeflection; and wherein the core second indentation force deflection isgreater than the second intermediate second indentation force deflectionand the second intermediate second indentation force deflection isgreater than the second outer second indentation force deflection. 15.The therapeutic body support apparatus of claim 14, wherein the corefoam portion comprises polyurethane foam.
 16. The therapeutic bodysupport apparatus of claim 15, wherein the core density is between about2.5 pounds per cubic foot and about 3.0 pounds per cubic foot.
 17. Thetherapeutic body support apparatus of claim 14, wherein the coreindentation force deflection is in the range from about 75 pounds/fiftysquare inches to about 90 pounds/fifty square inches at twenty fivepercent deflection.
 18. The therapeutic body support apparatus of claim14, wherein the first intermediate foam portion comprises polyurethanefoam.
 19. The therapeutic body support apparatus of claim 18, whereinthe intermediate density is in a range from about 2.5 pounds to about3.0 pounds per cubic foot.
 20. The therapeutic body support apparatus ofclaim 14, wherein the intermediate indentation force deflection isbetween about 29 pounds/fifty square inches and about 39 pounds/fiftysquare inches at twenty five percent deflection.
 21. The therapeuticbody support apparatus of claim 14, wherein the outer foam portion hasan indentation force deflection in the range from about 19 pounds/fiftysquare inches to about 25 pounds/fifty square inches at twenty fivepercent deflection.
 22. The therapeutic body support apparatus of claim21, wherein the outer foam portion has an indentation force deflectionof about 24 pounds/fifty square inches at twenty five percentdeflection.
 23. The therapeutic body support apparatus of claim 14,further comprising a raised ridge proximate at least a portion of aperimeter of the apparatus.
 24. The therapeutic body support apparatusof claim 23, wherein the raised ridge is interrupted by a cut away sizedto receive an appendage of a body of a person lying on the apparatus.25. The therapeutic body support apparatus of claim 14, wherein theapparatus is a mattress.